The present invention relates to a method and an apparatus for manufacturing tubular items, particularly hosiery items, closed at an axial end.
It is known that hosiery items are generally manufactured on circular hosiery knitting machines and that in the conventional manufacturing method they are unloaded from the machine while their toe is still open and must be subjected to subsequent sewing or looping in order to form the finished product.
Since the sewing or looping operation requires a manual intervention of an operator to load the hosiery item on the looping or sewing machine, this operation has a significant effect on the overall manufacturing costs of hosiery items.
For this reason, methods and devices have been devised in recent years which are adapted to obtain hosiery items having a closed toe directly on the machine that manufactures them or are adapted to mechanize the transfer of the hosiery items from the machine that produces them to the looping or sewing machine in order to fully eliminate, or at least substantially reduce, manual interventions for performing this operation.
In some of these methods, for example in the method disclosed in Italian Patent No. 1,277,396 in the name of the same Assignee, the hosiery item is started from the opposite end with respect to the toe, i.e., from the top of the leg, and is completed at the toe, retaining the last row of knitting on the needles of the machine. Such last row is then transferred, loop by loop, from the needles of the circular machine to the hooks supported by an annular element which is arranged around the upper end of the needle cylinder. The annular element is divided into two halves which can overlap one another so as to overlap the loops of one half-row, carried by the hooks arranged in one half of the annular element, on the loops of the other halfrow, which are supported by the hooks of the other half of the annular element. In a subsequent step, the pairs of loops thus arranged side by side are sewn in order to join them thereby closing the toe of the hosiery item, which is then unloaded from the annular element.
The closure of the toe, performed with methods and devices of this kind, has the drawback that it is not fully satisfactory from an aesthetic point of view.
The joining of mutually adjacent pairs of loops by sewing in fact does not achieve a tight coupling of the loops that can be compared with the one obtainable by conventional sewing or looping.
The aim of the present invention is to solve the above problem by devising a method and an apparatus for manufacturing tubular items, particularly hosiery items, which are closed at an axial end and in which the closure of said axial end is fully satisfactory.
Within this aim, an object of the invention is to provide a method which allows to obtain a closure of an axial end of a tubular item which can be compared with the closure that can be obtained by means of conventional sewing or looping.
Another object of the invention is to provide a method which allows to manufacture tubular items, particularly hosiery items, which are closed at an axial end in a fully automated manner and therefore without requiring the manual intervention of an operator.
Another object of the invention is to provide an apparatus which allows to obtain tubular items, particularly hosiery items, which are closed at an axial end and can be installed easily on currently commercially available circular hosiery knitting machines.
This aim and these and other objects which will become better apparent hereinafter are achieved by a method for manufacturing tubular items, particularly hosiery items, closed at an axial end, comprising a step for forming the tubular item on a circular hosiery knitting machine by way of the needles of the needle cylinder, starting from the opposite axial end of the item with respect to the axial end to be closed and retaining on the needles of the needle cylinder the last formed row of knitting, characterized in that it comprises the following additional steps:
individually transferring the loops of the last formed row of knitting from the needles of the needle cylinder to an auxiliary element provided with supporting means for individually supporting the loops, the supporting means of at least one half-row of said last row being adapted to receive two loops and to form knitting;
reversing the item;
transferring the loops of one half-row from the corresponding supporting means to the supporting means engaged with the loops of the other half-row;
forming at least one additional row of knitting, closing the axial end of the item, with the supporting means that carry said half-rows;
unloading the item from said supporting means.
The method according to the invention is preferably performed by way of an apparatus for manufacturing tubular items, particular hosiery items, closed at an axial end, characterized in that it comprises a circular auxiliary element which can coaxially face the end of the needle cylinder that corresponds to the needle work area of a circular hosiery knitting machine, said auxiliary element being provided with supporting means which are adapted to individually receive the loops of a row of knitting formed and retained by the needles of the needle cylinder, the supporting elements of at least one half-row of said row of knitting being actuatable in order to form knitting.